2017-12-14T00:40:29ZMechanisms and strategies shaping plant peptide hormoneshttp://hdl.handle.net/2237/27071
Title: Mechanisms and strategies shaping plant peptide hormones
Authors: Yuki, Hirakawa; Keiko U., Torii; Naoyuki, Uchida
Abstract: Plant genomes encode a variety of short peptides acting as signaling molecules. Since the discovery of tomato systemin, a myriad of peptide signals, ranging in size, structure and modifications, have been found in plants. Moreover, new peptides are still being identified. Surprisingly, non-plant organisms, especially pathogens, also produce peptides which exert hormonal activities against host plants by hijacking their endogenous reception systems. In this review, we focus on short secretory peptides ranging from five to 20 amino acids. We first summarize recent advances in understanding relationships between the bioactivities and structures of plant peptide hormones. Subsequently, we introduce the topic of peptides produced by non-plant organisms. Lastly, we describe artificial peptides synthesized in laboratories, which possess intriguing bioactive properties beyond those of natural peptide hormones.2017-08-01T00:00:00ZWater-Soluble N-Heterocyclic Carbene-Protected Gold Nanoparticles: Size-Controlled Synthesis, Stability, and Optical Propertieshttp://hdl.handle.net/2237/26870
Title: Water-Soluble N-Heterocyclic Carbene-Protected Gold Nanoparticles: Size-Controlled Synthesis, Stability, and Optical Properties
Authors: Salorinne, Kirsi; Man, Renee W.Y.; Li, Chien-Hung; Taki, Masayasu; Nambo, Masakazu; Crudden, Cathleen M.
Abstract: NHC-Au(I) complexes were used to prepare stable, water-soluble, NHC-protected gold nanoparticles. The water-soluble, charged nature of the nanoparticles permitted analysis by polyacrylamide gel electrophoresis (PAGE), which showed that the nanoparticles were highly monodisperse, with tunable core diameters between 2.0 and 3.3 nm depending on the synthesis conditions. Temporal, thermal, and chemical stability of the nanoparticles were determined to be high. Treatment with thiols caused etching of the particles after 24 h; however larger plasmonic particles showed greater resistance to thiol treatment. These water-soluble, bio-compatible nanoparticles are promising candidates for use in photoacoustic imaging, with even the smallest nanoparticles giving reliable photoacoustic signals.2017-05-22T00:00:00ZTheoretical Study on Nonradiative Decay of Dimethylaminobenzonitrile through Triplet State in Gas-Phase, Nonpolar, and Polar Solutionshttp://hdl.handle.net/2237/26608
Title: Theoretical Study on Nonradiative Decay of Dimethylaminobenzonitrile through Triplet State in Gas-Phase, Nonpolar, and Polar Solutions
Authors: Suda, Kayo; Yokogawa, Daisuke
Abstract: The control of radiative and nonradiative decay is important in the design of bioimaging molecules. Dimethylaminobenzonitrile (DMABN) is a suitable model molecule to study radiative and nonradiative decay processes and has been investigated by theoretical and experimental methods. However, an atomistic understanding of the nonradiative decay in solutions remains to be achieved. In this study, we investigated the potential-energy surfaces in excited states along the rotation of the dimethylamino group and found that the degeneration between S1 and T1 states is one of the key factors in the nonradiative decay in polar solvents. In addition, we found that the degeneration is precisely controlled by a fundamental physical property, exchange integral. Although DMABN is a simple molecule, the understanding of the nonradiative decay process on the basis of physical properties should be useful in the design of more complicated imaging molecules.2017-02-16T00:00:00ZStem development through vascular tissues: EPFL–ERECTA family signaling that bounces in and out of phloemhttp://hdl.handle.net/2237/26600
Title: Stem development through vascular tissues: EPFL–ERECTA family signaling that bounces in and out of phloem
Authors: Tameshige, Toshiaki; Ikematsu, Shuka; Torii, Keiko U.; Uchida, Naoyuki
Abstract: Plant cells communicate with each other using a variety of signaling molecules. Recent studies have revealed that various types of secreted peptides, as well as phytohormones known since long ago, mediate cell–cell communication in diverse contexts of plant life. These peptides affect cellular activities, such as proliferation and cell fate decisions, through their perception by cell surface receptors located on the plasma membrane of target cells. ERECTA (ER), an Arabidopsis thaliana receptor kinase gene, was first identified as a stem growth regulator, and since then an increasing number of studies have shown that ER is involved in a wide range of developmental and physiological processes. In particular, molecular functions of ER have been extensively studied in stomatal patterning. Furthermore, the importance of ER signaling in vascular tissues of inflorescence stems, especially in phloem cells, has recently been highlighted. In this review article, first we briefly summarize the history of ER research including studies on stomatal development, then introduce ER functions in vascular tissues, and discuss its interactions with phytohormones and other receptor kinase signaling pathways. Future questions and challenges will also be addressed.2017-01-01T00:00:00Z